Yes, the headline translates as ”The new prime minister Renzi promises Italians more pizza”. I found the original article in Helsingin Sanomat, and it seems to me that the idea for the headline came from this paragraph:

”'The critics [of Renzi's plans] have no idea what it feels like to earn 1 500 euros a month with no chance of buying books for your children or go out for a pizza at least once a week,' Renzi said in an interview by the newspaper Corriere della Sera.”

I can't speak for the person who wrote the headline, but I don't know if it's making fun of Italians (as you were asking in the first post) -- it may just be an attempt at creating a clever-sounding headline, based on one of the things Renzi said to the press. Of course, that doesn't mean that the headline succeeds in being clever.

You see this sort of thing in English-speaking news, too: for example, there have been a couple of news stories about Russia that used the headline "Russian to judgement", which is a play on the expression rushing to judgement. I don't find these kinds of puns very funny, but people will probably continue using them as long as they grab the attention of readers.